3、Statement陈述接口的子接口提前准备sql语句PreparedStatement中的方法来执行SQL语句

importjava.sql.Connection;

importjava.sql.DriverManager;

importjava.sql.PreparedStatement;

importjava.sql.SQLException;

publicclassTestPrepStatement{

     publicstaticvoidmain(String[]args){

          if(args.length!=2){

              System.out.println("Parameter Error ! Please Input Again!");

              System.exit(-1);

          }

          Stringname=args[0];

          intage=0;

          try{

          age=Integer.parseInt(args[1]);

          }catch(NumberFormatExceptione){

              System.out.println("Parameter Error ! Age should be Number Format!");

              System.exit(-1);

          }

          

          PreparedStatementpstmt=null;

          Connectionconn=null;

          // 跟数据库连接先找到数据库管家DriverManager(连接哪种数据库)

          // new出来mysql驱动类-class.forname

          try{

              Class.forName("com.mysql.jdbc.Driver");

              // 此时会自动注册DriverManager,可以拿到跟数据库连接

              conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/tab_demo?useSSL=false","root","123456");

              // 现在已经连接到数据库上了,现在执行sql语句

              // 创建一个语句对象Statement陈述语句的意思

              Stringsql="INSERT INTO `tab_demo`.`inf` (`name`, `age`) VALUES (?,?)";

              pstmt=conn.prepareStatement(sql);

              //准备好的sql执行语句生成,下面给占位符赋值

              pstmt.setString(1,name);

              pstmt.setInt(2,age);

              

              intinsert=pstmt.executeUpdate();//执行数据库添加数据操作

              System.out.println(insert);

          }catch(ClassNotFoundExceptione){

              // 驱动找不到报异常

              e.printStackTrace();

          }catch(SQLExceptione){

              // 后面的SQL执行异常,通常记录在log文件里,用log for J开源框架记录在文件里

              e.printStackTrace();

          }finally{// 关闭资源

              try{

                   if(pstmt!=null){

                        pstmt.close();

                        pstmt=null;

                   }

                   if(conn!=null){

                        conn.close();

                        conn=null;

                   }

              }catch(SQLExceptione){

                   e.printStackTrace();

              }         }    }}